Drill bit



June 2, 1925- 1,540,048

c;. R. WATSON DRILL BIT Filed June 19', 1924 Fig. 3.

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At ornay.

Y GiiT/Vaaornby 5 County, Iowa,

Patented June 2, 1925.

UNITED STATES PATENT OFFICE.

T0 ARMSTRONG MAN UFACTUR- ING COMPANY, OF WATERLOO, IOWA.

DRILL BIT.

Application filed June 19,

To all who-n9. it may concern:

Be it known that I, GEORGE R. WATSON, a citizen of the United States of America, and a resident of Waterloo, Blackhawk have invented certain new and useful Improvements in Drill Bits, of which the following is a specification.

My invention relates to improvements in drill-bits, and the object of my improvement 1 is to supply for drilling rock strata, a drill wvhose bit is in shape contrived for great rapidity of drilling, and whose design is such as to impart to it great strength at places which sustain the most wearand 15 stresses in use.

This object I have accomplished by the means which are hereinafter described and claimed, and which are illustrated by the accompanying drawings, in which Fig. l is a side elevation of my improved drill and bit,

. with a part broken away.

Fig. 2 is an elevation thereof taken at an angle of ninety degrees to the elevation of said Fig. 1. Fig. 3 is a plan view of the bit end.

The drill shank 1 has at the top a central threaded and conical boss 2 adapted for engagement with a threaded socket in a drill stem. The body 3 of the drill is substantially octangular, having medial longitudinal grooves 6 in two opposite faces which in tel-sect the flat crushing face of the bit end 4 at a transverse groove 8, the intersecting grooves thus producing therebetween an upwardly hollowed or arcuate edge or ridge of anticlinal form 6-8. The lower ends of said side grooves (3 separate the dian1etrically widened cylindrical end part 4, the outer walls being separated from the grooves by flattened parts 7. The crushing face of the bit end is flat and has a pair of like depending anticlinal and diametrically v middle 1924. Serial No. 720,977.

alinedspaced ridges 11 which cross the face radially from the transverse groove and are reinforced at their outer extremities by means of angular abutments 10 on each side. These abutments whilesupplying reaming cutters, also serve to widen and strengthen the ends of the ridges 11 Where the most wear and stress occur in use. The abutments may be carried inwardly along the ridges 11 as far as desired, according to the hardness of the strata to be drilled.

The ridges chop up the rock at the bottom of the drill-hole about a domical projection of rock at and below the ridge 8, the latter centering the drill, and also breaking down the projection progressively.

Having described my invention, what I claim as new, and desire to secure by Letters Patent, is:

1. A drill-bit having a fiat crushing face interrupted by a transverse hollow Whose shapes and limits a diametrical upwardly arcuate ing depending cutters extending toward said arcuate ridge and diminishing in width from their outer ends inwardly.

2. A drill-bit having a crushing face with cutting ridges depending therefrom and extending from its outer periphery inwardly, said ridges also diminishing in width from their outer ends inwardly.

3. A drill-bit having a tabular crushing face supplied with cutting ridges extending from its outer periphery inwardly, and said ridges having angularly widened outer terminations whose outer angles serve as reaming cutters and which serve as reinforcements at their outer ends.

Signed at Waterloo, Iowa, this 15th day,

of .May, 1924.

GEORGE R. WATSON.

cutting ridge, said bit hav- 

